Hangouts/prepaid/unlocked phone?

I have the new Hangouts, integrated my GV number and so far it seems awesome. called my GV #, left a message and saw the "voicemail" written out on my phone and a button in hangouts to actually listen to the VM....no need to call my VM #....very cool

Now I'm wondering if I could drop my verizon plan, get a prepaid phone or an unlocked phone and buy the data only prepaid cards and use wifi/data, using hangouts to make all my calls? Is this correct???
Or do i still need to be attached to a carrier somehow? and if so, again just go prepaid and just buy the data only cards?

Yes you could. It would depend on what prepaid as I'm not 100 percent sure they all support Google voice. I know T-Mobile supports Google voice integration so that would be an option. Who were you thinking about going with?